Interactions in vitro between sporozoites of Eimeria tenella and host peritoneal exudate cells: electron microscopal observations.

The interactions of sporozoites of Eimeria tenella with peritoneal cells from normal and from immunized chickens were examined in vitro. Although the uptake of sporozoites by cells from immunized birds was greater than by cells from susceptible birds, no differences were apparent in their appearance in electron micrographs. Entry into both macrophages and heterophils (comparable to mammalian neutrophils) was by phagocytosis. The findings are discussed.